Polishing machine



Patented Apr. 2, 1940 PATENT OFFICE POLISHING MACHINE Howard W. Dunbar, Worcester, and Herbert S. Indxe, Wostboro, Mass, assignors to Norton Company, Worcester, Mass, a corporation of Massachusetts Application August 13, 1937, Serial No. 158,989 1 Claim. (Cl. 51-154)v The invention relates to abrading machines and w.'th regard to its more specific features to polishing machines.

One object of the invention is to provide a through feed polishing machine. Another object of the invention is to provide a. machine for polishing small cylindrical objects such as rolls and the like. Another object of the invention is to provide a machine of high capacity production for polishing cylindrical objects. Another object of the invention is to provide an abrading machine of such character that the abrasive action can be readily varied. Another object of the invention is to provide a polishing or lapping machine requiri g no dressing or truing of any parts. Other ob ects will be in part obvious or in part pointed out-hereinafter.

The invention accordingly consists in the features of construction, combination of elements,

and arrangements of parts as will be indicated in the structure to be hereinafter described, and the scope of the application of which will be pointed out in the following claim.

' In the drawing illustrating one of many possible embodiments of the mechanical features of this invention,

Figure 1 is a view partly in vertical section and partly in front elevation of a machine constructed in accordance with the invention;

Figure 2 is an end elevation;

Figure 3 is a horizontal sectional view taken on the line 3-3 of Figure 2;

Figure 4 is an enlarged fragmentary sectional view taken on the line 4-4 of Figure 1.

Referring first to Figures 1, 2 and 3, we provide a machine base I 0 having at the rear thereof an uprising column H. A vertical slide l2 has a nut l3 aflixed to it through which passes a screw shaft N that is journalled in a thrust journal l5 at the top of the column II. A hand wheel I6 is secured to the upper end of the screw shaft l4 and by means thereof the operator can raise and lower the slide l2. A dial l1 may be provided to assist the operator in locating the slide l2.

Referring to Figures 1 and 2, the base ID has on the upper side thereof ways 20 supporting for movement in a horizontal plane a slide 2|.

Depending from the slide 2| is a nut 22 through which passes a screw shaft 23 extending to the front of the machine and having aflixed thereon a hand wheel 24. By rotating the hand wheel 24 the slide 2| may be moved forwardlyor rearwardly of the machine frame It. A dial 25 similar to the dial I'I may be provided to assist the operator in his calculations.

Referring now to Figure 1, uprisingjrom the left hand side of the slide 2| is a journal portion 4 25. Referring to Figures 1 and 2, on the right hand side of the slide 2| as it is viewed in Figure 1 are dove-tailed ways 21. A journal member 28 having dove-tailed ways complementary to the ways 2'! fits upon these ways 21 and uprises from the right hand end of the slide 2|. Referring 10 now to Figure 3, the journal members 25 and 28 journal a shaft 29 upon which is mounted an abrasive cylinder 30. The abrasive cylinder 3|! is preferably made of a plurality of cylindrical abrasive members mounted in axial alignment 15 as shown. The abrasive members making up the cylinder 30 may consist of any one of the usual abrasives, such as silicon carbide, silica or fused alumina, and preferably the latter is used. The abrasive particles may be bonded with any one '0 of the usual or known bonds including vitrified clay and other ceramic bonds, natural resins such as, shellac, synthetic resins, rubber, and other types. The phenolic condensation product resin gives many practical advantages in a ma- 2 chine of this class. Suitable flanges and nuts 3|, 32, 33, 34 and 35 may be used to mount the wheel 39 upon the shaft 29. For assembly purposes the left hand end of the shaft 29 is first placed in the journal member 25 and then the 30 journal member .28 may be slid into position.

Still referring to Figure 3, fastened to the shaft 29 is a double sprocket member 95 having sprocket gear portions 31 and 38. A chain 99 connects the sprocket gear 31 with a sprocket a gear 40 fastened to the armature shaft 4| of a motor 42. The motor 42, as best shown in Figure 2, is secured to a rearwardly extending portion 43 of the slide 2|.

Referring now to Figures 1 and 2, mounted on 40 the front of the machine is an angularly adjustable supporting member 45. The member 45 has arcuate slots 48, 46 through which extend bolts 41, 41, the bolts extending into the machine frame "I and serving to lock the supporting 45 member 45 to the machine frame. Extending upwardly from the left hand side of the supporting member 45 as viewed in Fi ure 1 is a journal portion 48. On the right hand side of the supporting member 45 are ways 49 similar to the ways 21. A journal member 5|! has dovetailed ways on the bottom thereof which are complementary to the ways 49. and the member iI-flts upon these ways and uprises from the right hand end of the supportingmember 45. ll

The journal members 48 and 50 Journal a shaft 5| upon which is mounted a. pseudosphere 82. This pseudosphere may be made up of a. plurality of abrasive members mounted in axial alignment as shown, and these abrasive members may be of the same type as those which make up the cylinder 30. On the other hand, however, the cylinder 30 as well as the pseudosphere 52 may be a solid piece of steel or cast iron, or only the pseudosphere 52 may be of metal. It is contemplated that this machine will preferably function without the use of any dressing device or the like. Accordingly the member 52, whether a composite member made of many abrasive sections or a solid abrasive member or a solid piece of steel or cast iron, or of any other form, is preferably shaped outside of the machine into pseudospherical form or shape, which is defined as that shape which will receive in tangent relation a cylindrical work piece and along which the cylindrical work piece may be pushed while maintaining the condition of tangency. Sumciently accurate results in the manufacture of such shapes can now be achieved so that the finished pseudosphere may be placed in the machine of the present invention where it will perform its work for a long time before requiring reshaping. As shown in the drawing, the pseudospherical member 52 is inclined to the horizontal while the wheel 30 has its axis in a horizontal plane. This results in a feeding component upon a work piece as the two wheels are rotated in the direction of the arrows as shown in Figure 1. The exact pseudospherical shape adopted depends upon the angle of skew, and the angle of skew havin been predetermined, the member 52 is shaped accordingly. However, errors in manufacture may be substantially compensated for b the adiustment of the supporting member 45 between the bolts 4'! and the long slots 46.

The pseudospherical member 52 which, the

same as the cylindrical member 30 is a work holding and rotating member, is positively driven by means of a chain 55 passing around the sprocket 38 and around a sprocket 58 secured to the shaft 5|. The pseudospherical member 52 is mounted u on shaft 5| 'by means of flanges and nuts 51, 58. 59, 60, and BI and the shaft BI s placed in its journals in the same manner in which is placed the shaft 29.. A work piece W introduced at the left hand end of the machine is su ported by the members 30 and 52, rotated by them, and propelled to the right, Figure 1, by the skewed su porting member 52. For the pol shing of different sizes of work pieces the supnortina cylinder 30 may be moved horizontallv to different positions by turning the hand wheel 24.

Referring now to Figure 1, projecting forwardly from the left hand side of the slide I2 is a journal support 65. Similarly projecting forwardly from the right hand side of the slide I2 is a portion thereof having dove-tailed ways 81 for holding a journal member 68. Extending between the journal members 65 and 68 and supported thereby is a shaft III to the left hand end of which is attached a worm wheel 1|. Meshing with the worm wheel II is a worm 12 mounted on a shaft 13 which is joumalled in a bracket I4 attached to the journal member 65. Referring now to Figures 1 and 2, attached to the rear end of the shaft 13 is a gear 15. A wheel I8 having a single tooth I1 is mounted adjacent the gear I5 in such position that the tooth 11 will engage the gear Ill to drive it one tooth at a time. The wheel 10 is mounted on the armature shaft 18 of a motor I! which is supported by a bracket 8: formed integral with the slide l2. At every revolution of the motor shaft 18 the gear 15 is moved by the distance of one tooth which, by way of the reduction gear involving the worm I2 and worm wheel 1| slowly and intermittently revolves the shaft 10. Secured to the shaft 10 is a cylinder 80, for example a hollow cast iron cylinder. Extending upwardly from the journal support 82 is a bracket 8| removably-supporting a bracket Ola having a journal portion 82. Extending upwardly from the journal portion I is a bracket 82 having a journal portion ll. A shaft ll extends between the journal portions I2 and 84. A let-off drum 86 which may be made of wood has suitable flanges 81 and is mounted upon and secured as by set screws 22 to the shaft II. A roll of sandpaper II is wound upon the let-oif drum 8! and the sandpaper "a as shown in Figure 2 extends downwardly and around the cylinder lll.

Referring now to Figures 1 and 2, extending forwardly from journal members 65 and l are studs II and 82. Mounted on these studs SI and 52 are Journal members. 93 and 94 supporting a small cross roller 95 located in front of the cylinder 80. Springs 96 located on the studs II and 92 and backed up by collars l1 urge the journals 93 and 94 rearwardly of the machine thus pressing the roller 9! toward the cylinder 80. The sandpaper "a extends half way around the cylinder and between the cylinder 8|! and the roller 95, then half way around the roller 95 where it hangs downwardly.

Referring now to Figures 1, 2 and 4, extending forwardly from the journals 9! and N are bosses I00 and II". By means of bolts I02 and III a knife blade III is secured to the bosses I and HM. This knife blade I extends across and in front of the roller I. The end of the sandpaper Sfla extends downwardly between the back of the knife blade ill and the roller 2!. When this depending end becomes too long the operator simply presses the paper upwardly against the blade HM and tears off a portion of the sandpaper which has been used and may be discarded. This clears the machine of accumulations of sandpaper.

The work piece W revolves in such direction that it pulls the sandpaper down from the drum 86. The shaft 88 is intermittently indexed in a counterclockwise direction, Figure 2. We provide braking means to prevent the let-off drum 88 from spinning and to hold the sandpaper taut. As shown in Figures 1 and 2, the bracket 82 has an upwardly extending L-shaped portion llll providing a Journal III for a vertically movable stud H2 having a collar Ill secured thereto. A spring H4 presses the collar HI and therefore the stud I I2 downwardly. Secured to the bottom of the stud H2 is an arcuate brake member H5 having a brake lining H8 engaging the outer end of the shaft 85. This constitutes a brake to hold the paper a in a taut condition and not only keeps the let-off drum 86 from spinning but also holds back the cylinder 20 by holding the paper taut. By reason of the drive and let-oi! described, the sandpaper is held to the cylinder 20 in a smooth condition.

The work piece W is fed through the machine from left to right (Figure 1) at the same time that it is rotated and supported by the rolls II and 52. The sandpaper polishes the work piece W and the abrasive surface is constantly renewed by the angular indexing mechanism described. The amount of pressure between the work piece and the rolls ll and 52 and the sandpaper 90a may be varied by adjusting the hand wheel IS. The hand wheel I20 secured to the shaft 13 is provided for initially setting up the machine or feeding the sandpaper more rapidly if desired.

The term "sandpaper" is used generically to include all coated abrasive materials, and the backing may be paper or cloth or other flexible material. The abrasive may be ordinary quartz sand but fused alumina abrasive is preferred. Also other abrasives might be used such as silicon carbide, garnet, or emery.

By'means of this machine a very fine polish can be imparted to a cylindrical work piece such as a roll. Grinding lines are rapidly removed by passing a work piece through this machine. Since the abrasive surface is constantly renewed the machine does not have to be shut down for adjustments or for truing. Since the rolls and 52 merely feed the work piece they are found to last a long time. The rolls III and 52 may be made of metal as aforesaid thus saving considerable in the cost thereof. However, for certain other uses of the machine, the longer lived abrasive rolls 30 and 52 will be preferred.

' A wide range of different sizes of work piece may the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawing, is to be interpreted as illustrative and not in a limiting sense.

We claim:

In apparatus of the class described a pair of driving and rotating rolls which are in skewed relation to each other, that is to say their axes are at a slight angle to each other, one of said rolls being pseudo-spherical in shape to a degree to compensate for the relative skew between the rolls in order to hold a work piece with a line contact, means for positively rotating one of said rolls, a third normally stationary roll parallel to one of the first two rolls and located to form with them a throat for polishing a work piece, a supply reel for coated abrasive material,

and an intermittent drive for the third roll intermittently to feed the coated abrasive material to present further portions thereof to polish the work piece, whereby the first two rolls rotate a HOWARD w. DUNBAR. HERBERT s. INDGE. 

